Like many school districts, Broward County’s allows high school students to bring cellphones to school, so long as they don’t interfere with class work. On Wednesday, many students at Marjory Stoneman Douglas High School held onto their phones for dear life. They used them to keep their terrified parents informed about what was happening. And they used them to keep a visual record of an awful crime.

Sarah Crescitelli, a freshman, was in drama class rehearsing for a coming run of the musical “Yo, Vikings,” when gunshots rang out.

Hiding in a sweltering storage room with about 40 other students, she typed out a text message to her mother, Stacy, for what she thought might be the last time.

“If I don’t make it,” she wrote, “I love you and I appreciate everything you did for me.”

Some of the alarming videos of the mass shooting that took place Wednesday were passed around via text message, while others quickly made their way to Twitter, where they triggered “sensitive material” warnings.

One video showed officers with guns drawn, rushing into a classroom full of cowering students. The officers told students to put up their hands. One officer bellowed: “Put your phones away! Put your phones away!”

‘The Safest Community in the County’

Parkland is the type of community where affluent young parents move to find verdant parks and pristine sidewalks for their children. Most everybody knows somebody at Stoneman Douglas High, home of the Eagles.

A famous alumnus of MSD, as the school is widely known, is Anthony Rizzo, who plays first base for the Chicago Cubs. Sheriff Scott Israel, who was briefing journalists on the tragedy inside the school, has triplets who graduated from MSD and played football and lacrosse and ran track there. Israel said one of his deputies had learned that his son had been injured in the attack.

State Rep. Jared Moskowitz, who graduated from MSD in 1999, sends his 4-year-old to a preschool down the street.

The high school, with more than 3,000 students, is almost a city within a city, with airy breezeways and an open courtyard. It bears the name of Stoneman Douglas, the famed environmentalist who crusaded against paving over the Everglades.

“It’s surreal,” Moskowitz said. “People don’t come to Parkland to open a business. They come to Parkland to raise a family. They come to Parkland to send their child to an A-rated school. They come to Parkland to live in the safest community in the county.”

A Day That Began With ‘Life’

Every morning at Stoneman Douglas High begins with an affirmation, which is read over the intercom. On Wednesday morning, the affirmation began with the word life.

“Life supports me in every way possible,” were the first words students heard that day.

The announcement went on to speak of Valentine’s Day and how everyone “deserves a safe and healthy relationship.”

The Astronomy Club announced it was celebrating Black History Month on Thursday night with a showing of the movie “Hidden Figures.” But that event was postponed, as Stoneman Douglas canceled all school events and called in grief counselors.

The Drill That Wasn’t

Was it another drill? There had been a fire drill earlier that day. Some weeks back, there had been an active-shooter drill.

Alarms were blaring Wednesday afternoon. Students were scurrying around. Some were convinced it was one more readiness test.

“When we first heard the two gunshots, nobody did anything because we thought that was a drill,” Masiel Baluja, a student, told CNN.

Confusing the situation, a fire alarm had been activated shortly before the shots began, perhaps an effort by the assailant to sow confusion.

Gabriella Figueroa, 16, a junior, had been in geometry class working on angle bisectors when the alarm sounded. As she neared the exit doors, she heard the first gunshots and ran back to class. “I was shaking and praying and saying, ‘God, please get me out of here,'” she said.

Melissa Falkowski, a teacher, told CNN, “We could not have been more prepared for this situation, which is what makes it so frustrating.”

She continued: “We have trained for this, we’ve trained the kids for what to do, and so the frustration is that we’ve done everything we were supposed to do.”

And still people died, 17 of them, children and adults, most of them unidentified by authorities as of Wednesday night. One of the complications, the sheriff said, was that the students’ identifications were still in their backpacks, which they had left behind in the havoc.